View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by OpenGrey Repository CHARACTERISATION OF VIRTUAL POWER PLANTS A thesis submitted to the University of Manchester for the degree of PhD in the Faculty of Engineering and Physical Sciences 2010 Guy Newman School of Electrical and Electronic Engineering Index Table of Contents Table of Contents ...........................................................................................................2 List of Figures ............................................................................................................4 List of Tables..............................................................................................................6 Abstract ..........................................................................................................................7 Declaration .....................................................................................................................8 Copyright Statement ......................................................................................................8 Acknowledgements........................................................................................................9 List of Publications ........................................................................................................9 Chapter 1 Introduction..............................................................................................10 1.1 Background ..................................................................................................10 1.1.1 The Virtual Power Plant (VPP)............................................................12 1.1.2 Weather forecasting and the VPP ........................................................14 1.1.3 The VPP and electricity markets..........................................................15 1.2 Scope and Objectives of this Research ........................................................17 1.3 Main Achievements and contributions of this work ....................................20 1.3.1 Development of a Probabilistic, Domestic CHP Model ......................20 1.3.2 Development of Four Different VPP Prediction Models.....................21 1.3.3 Wide Area Support for VPP Power Prediction....................................22 1.3.4 Network Effects Incorporated into the VPP Model .............................23 1.3.5 Modelling Network Security Impacts on VPP.....................................23 1.4 Chapter Summary.........................................................................................24 Chapter 2 Overview of the Virtual Power Plant.......................................................26 2.1 Introduction..................................................................................................26 2.2 The Virtual Power Plant...............................................................................27 2.3 Wind Turbines..............................................................................................31 2.4 Photovoltaic Arrays......................................................................................33 2.5 Micro Combined Heat & Power ..................................................................34 Chapter 3 Predicting the VPP Power Output............................................................36 3.1 Introduction..................................................................................................36 3.2 Uncertainty in Wind Power Forecasting......................................................40 3.2.1 Air Density...........................................................................................43 3.3 PV Basics .....................................................................................................44 3.3.1 Clearness and Diffusion Index.............................................................50 3.4 Micro Combined Heat & Power Basics.......................................................50 3.5 Aggregating Generator Outputs...................................................................58 Chapter 4 Improving the VPP Prediction Model......................................................63 4.1 Introduction..................................................................................................63 4.2 The 5 Point Forecast Approach....................................................................66 4.3 Raw NWP Data Approach...........................................................................71 4.4 Technology Model Improvements...............................................................73 Chapter 5 Modelling Networks Effects in VPP........................................................81 5.1 Introduction..................................................................................................81 5.2 Modelling the Network ................................................................................85 5.3 Incorporation of Tap changers .....................................................................90 5.4 Changes to the Model to Allow the Network...............................................97 5.5 Network Security Assessment......................................................................99 5.5.1 N-1 Analysis ......................................................................................100 2 Index Chapter 6 Implementation and validation of the VPP Models...............................102 6.1 Model Validation .......................................................................................102 6.1.1 Wind Turbine Model Verification .....................................................102 6.1.2 PV Array Model Verification.............................................................103 6.1.3 MicroCHP..........................................................................................104 6.2 Basic Uncertainty Results..........................................................................104 6.3 Results from the Advanced Uncertainty Work..........................................116 6.3.1 Drawbacks and Advantages of the Broader Models..........................118 6.3.2 Technology Profile Improvements.....................................................119 6.4 Financial Analysis......................................................................................121 6.4.1 Financial Impact of the Different Prediction Methods ......................122 6.4.2 Optimising Revenue for the VPP.......................................................123 6.4.3 ROCs and FITs...................................................................................128 6.5 Network Analysis.......................................................................................129 6.5.1 Voltage Limits....................................................................................129 6.5.2 Line Limits.........................................................................................132 6.5.3 N-1 Analysis ......................................................................................133 Chapter 7 Conclusion and Further Work................................................................137 7.1 Main conclusions .......................................................................................137 7.2 Suggestions for Further Work....................................................................140 References..................................................................................................................142 Appendix A Building the Toolset ..............................................................................151 The Basic Power Aggregator Tool.........................................................................151 Inputting Data.....................................................................................................152 Outputting Data..................................................................................................153 Augmentation of the Basic Process ...................................................................155 Optimization of the Basic Process .....................................................................156 The Load-Flow Tool with Aggregation .................................................................160 Scripting.............................................................................................................163 Populating the Network......................................................................................166 N-1 in the Network.............................................................................................168 Appendix B Publications ...........................................................................................171 Introduction............................................................................................................171 Characterising Virtual Power Plants ......................................................................172 Characterising the VPP ..........................................................................................188 Abstract ..............................................................................................................188 Introduction........................................................................................................188 Technology breakdown......................................................................................188 Long period power .............................................................................................192